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US3487880A
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Variable pitch fans
Assignee: Dowty Rotol Ltd
•
Filing: 1967-04-12
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Granted: 1970-01-06
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Expires: 1987-04-12
Abstract
No abstract record available.
Inventors
- 👤 Stuart Duncan Davies
- 👤 John Alfred Chilman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:36
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/32; F04D29/321; F04D29/322; F04D29/323; F01; F01D; F01D7/00; F02; F02K; F02K1/00; F02K1/54; F02K1/64; F02K1/66; F05; F05D; F05D2220/00; F05D2220/30; F05D2220/36; F05D2260/00; F05D2260/70; F05D2260/74; F05D2260/76; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2284938A
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US2316940A
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US2844303A
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US2969118A
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US2939536A
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US3054458A
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US3021696A
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US3130677A
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US3159221A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-01-05 | 1973-07-07 | 1974-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-01-05 | 1977-07-07 | 1978-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-01-05 | 1981-07-07 | 1982-01-06 | $7700.00 | Window Closed / Lapsed |